/* 菜单 */

/* 页眉 */
header {
    position: fixed;
    left: 0;
    top: 0;
    width: 100%;
    height: 98px;
    background-image: url(../images/index_bg.png);
    z-index: 200;
}

.header_top {
    height: 100%;
    margin: 0 auto;
    display: flex;
    box-sizing: border-box;
    color: #fff;
    width: 83.3333%;
    max-width: 1600px;
    position: relative;
}

/* header左上Logo和文字 */
header .top_logo {
    display: flex;
    height: 100%;
    color: #fff;
}

header .top_logo .logo_img {
    display: flex;
    align-items: center;
    min-height: 9.8rem;
    padding: 0 0.5rem;
}

header .top_logo .logo_img img {
    margin-right: 1rem;
}

.school_logo {
    height: 65.6%;
}

.college_logo {
    height: 61%;
}

/* 文字 */
.logo_text {
    display: flex;
    flex-direction: column;
    align-self: center;
    width: 23.2rem;
}

.big_text {
    font-size: 2.6rem;
    letter-spacing: 0.3rem;
    font-weight: 700;
}

.samll_text {
    font-size: 1.2rem;
    transform-origin: left;
    zoom: 0.65;
}

/* 导航栏 */
/* 小导航栏 */
/* padding:上 右 下 左 */
.nav {
    flex: 1;
    padding-left: 15px;
}

.top_nav1 ul {
    text-align: right;
    height: 4rem;
    width: auto;
    padding-top: 10px;
    box-sizing: border-box;
    color: #CCCCFF;
    font-size: 13px;
    display: flex;
    justify-content: end;
}

.top_nav1 ul li {
    justify-content: center;
    height: 100%;
    margin-right: 20px;
}

.top_nav1 ul li a {
    height: 100%;
    width: 100%;
    color: #CCCCFF;
    vertical-align: baseline;
}

.top_nav1 a img {
    width: 20px;
    margin-right: 5px;
    vertical-align: text-bottom;
}

.temp_search {
    width: 4.4rem;
    height: 2.8rem;
    border-radius: 4px;
    background-color: transparent;
    overflow: hidden;
    transition: all 0.35s;
}

.temp_search img {
    display: flex;
    justify-self: center;
    width: 2.2rem;
    height: 2.2rem;
}

.nav1_search {
    display: none;
}

/* 大导航栏 */
.top_nav2 ul {
    display: flex;
    width: 100%;
    height: 58px;
    line-height: 58px;
    font-size: 18px;
    font-family: Microsoft YaHei;
    font-weight: 400;
    justify-content: space-between;
}

.top_nav2 ul li {
    text-align: center;
    cursor: pointer;
    height: 100%;
    position: relative;
    padding: 0 5px;
}

.top_nav2 ul li a {
    text-decoration: none;
    color: #fff;
    display: block;
    height: 100%;
}

.top_nav2 ul li {
    text-align: center;
    height: 100%;
    position: relative;
    padding: 0 5px;
    cursor: pointer;
}

/* 子项 */
.top_nav2 ul li .item {
    line-height: 1.3em;
    height: auto;
    position: absolute;
    top: 58px;
    left: 50%;
    width: 100%;
    min-width: 10rem;
    transform: translateX(-50%);
    background: rgba(255, 255, 255, 0.95);
    box-shadow: 0px 2px 4px 0px rgb(0 0 0 / 35%);
    display: flex;
    flex-direction: column;
    text-align: left;
    padding: 20px;
    box-sizing: border-box;
    display: none;
}

.top_nav2 ul li .item li {
    text-align: center;
    padding: 0;
    margin-top: 0.5rem;
}
.top_nav2 ul li .item :hover a{
    color: #996600;
}

.top_nav2 ul li .item .first_item {
    margin-top: 0;
}

.top_nav2 ul li .item li a {
    text-decoration: none;
    display: block;
    color: #666;
    font-size: 14px;
}

.top_nav2 ul li:hover .item {
    display: flex;
}

/* 宽150px */
.top_nav2 ul li .w_150 {
    width: 15rem;
}

/* 宽180px */
.top_nav2 ul li .w_180 {
    width: 18rem;
}

/* 机构设置 */
.top_nav2 ul li .special_item {
    height: auto;
    width: 60rem;
    
    position: absolute;
    top: 58px;
    left: 50%;
    transform: translateX(-50%);
    background: rgba(255, 255, 255, 0.95);
    box-shadow: 0px 2px 4px 0px rgb(0 0 0 / 35%);
    display: flex;
    justify-content: space-between;
    text-align: left;
    padding: 20px;
    box-sizing: border-box;
    display: none;
}
/* .top_nav2 ul li .special_item li :hover a{
    color: #996600;
} */
.top_nav2 ul li .special_item li{
    line-height: 1.3em;
    text-align: left;
    display: flex;
    flex-direction: column;
    height: auto;
    padding: 0;
}
.top_nav2 ul li .special_item .k1{
    width: 19.6rem;
}
.top_nav2 ul li .special_item .k2,
.top_nav2 ul li .special_item .k3{
    width: 156.79px;
}
.top_nav2 ul li .special_item li ul{
    display: flex;
    flex-direction: column;
    height: auto;
}
.top_nav2 ul li .special_item li ul li{
    width: auto;
    height: auto;
    margin-top: 5px;
}
.top_nav2 ul li .special_item li ul li a{
    text-decoration: none;
    display: block;
    color: #666;
    font-size: 14px
}
.top_nav2 ul li .special_item li ul li:hover a{
    color: #996600;
}
.top_nav2 ul li .special_item .title_item{
    font-weight: bold;
    text-decoration: none;
    display: block;
    color: #666;
    font-size: 14px;
}
.top_nav2 ul li .special_item .k1 .h_y:hover .title_item,
.top_nav2 ul li .special_item .k2 .h_y:hover .title_item{
    color: #996600;
}
.top_nav2 ul li .special_item .math{
    width: auto;
    height: auto;
}

.top_nav2 ul li:hover .special_item {
    display: flex;
    justify-content: space-between;
}
/* 伪元素 */
.symbol::before{
    content: '';
    position: absolute;
    left: -10px;
    top: 50%;
    transform: translateY(-50%);
    width: 5px;
    height: 5px;
    background-color: #cca84d;
}
/* 研究所和教学系得伪元素 */
.symbol_sp::before{
    content: '';
    position: absolute;
    left: -10px;
    top: 5%;
    transform: translateY(-50%);
    width: 5px;
    height: 5px;
    background-color: #cca84d;
}
/* 固定首页 */
/* 三角形 */
.top_nav2 ul li .sy::before,
.top_nav2 ul li:hover .n_sy::before{
    content: '';
    position: absolute;
    bottom: 5px;
    width: 0;
    height: 0;
    left: 50%;
    transform: translateX(-50%);
    border-bottom: 6px solid #CCA84D;
    border-left: 10px solid transparent;
    border-right: 10px solid transparent;
    border-top: none;
}
/* 下划线 */
.top_nav2 ul li .sy::after,
.top_nav2 ul li:hover .n_sy::after{
    content: '';
    position: absolute;
    left: 0;
    bottom: 0;
    width: 100%;
    height: 5px;
    background-color: #CCA84D;
}